This invention relates generally to methods of synthetic fiber fabric reinforcement or repair and more particularly concerns a patch or reinforcing swatch of material for such fabrics and a process developed which enables so-called "iron-on" repair to be performed.
While iron-on canvas and denim patches and methods for applying these patchess are known in the art, the development of a weatherproof synthetic fiber fabric repair of similar nature has been impeded by a number of perplexing problems.
First, individual fiber strands or threads of a number of synthetic fabrics (for example, nylon, a material woven of synthetic polyamide fibers) have smooth regular unroughened exterior surfaces. These smooth exterior surfaces make it difficult to successfully apply a heat-activated adhesive type repair because there is relatively little rough surface area and interstices into which the adhesive may flow and bond when heat activation occurs. These factors tend to result in a repair fabric which will easily peel off or pull away from fabric to which it is applied.
Second, synthetic fiber fabrics are generally substantially less resistant to heat damage than are cotton and other natural fiber fabrics. In practice, it is possible to scorch or significantly damage some nylon fabrics at temperatures in the vicinity of 300.degree. Fahrenheit (F). This additional constraint complicates obtaining a reliable nylon or other synthetic fiber repair using a patch with heat-activated adhesive, because the adhesive activation temperature should be higher than garment temperatures normally encountered (e.g. 120.degree. F.), yet lower than the temperature at which the fabric may be damaged.
Despite these obstacles, fabric repair using patches have heat-activated adhesives is desirable because such patches require a minimum of user contact with the adhesive and permit the adhesive to be uniformly applied to one surface by a production process rather than by the user. Furthermore, liquid adhesives may often be suspended in a highly volatile and/or inflammable vehicle. This renders them hazardous to use in unventilated environments and creates source of irritation to the user.
In response to this need Applicants have developed and discovered a process for the reinforcing or repair of fabrics woven of synthetic fibers in which a reinforcing patch or swatch may be applied by use of an ordinary household garment pressing iron. Use of this process has been demonstrated to result in reliable and waterproof patching and reinforcing of synthetic fabrcis such as nylon.